Today, I got let go from my job, because my personal cell phone doesn't always have signal, so I missed an important call from work. My contract specifically said I'd get a work phone, which never happened. FML

He does have a case for breach of contract. If it was in writing he has a case for lost wages and severance as well as compensation for looking for a new job. It's important that he can prove he was fired for his phone though.

You should have a copy of the contract or it should be easy to dig up. Highlight the clause about the company phone and tell them that they owe you an explanation, the company phone and your job back. Don't go in w/o HR present, it will become "he said, she said" otherwise